The molecules in a crystalline solid are arranged in a crystal lattice, a three dimensional structure in which structural units (unit cells) are repeated in a regular manner. Different crystal forms of the same substance (polymorphs) have distinct crystal lattices, which can result in important differences in their properties, utilities, and commercial values. For example, graphite and diamond are polymorphs of crystalline carbon. Polymorphs of pharmaceutical compounds can also be distinctly, if not as dramatically, different in their properties, including properties relevant to the development of formulations of such pharmaceutical compounds and to the development of solid dosage forms, such as tablets and capsules, comprising such formulations. The crystal form of a drug may also be relevant to compliance with regulatory requirements concerning its manufacture.
ACH-0142684 sodium salt has been identified as useful for the treatment of chronic HCV infection. To improve therapeutic use of ACH-0142684 sodium salt, identification of new polymorphs of ACH-0142684 sodium salt would be desirable.